C/C++ 时间 & 日期

C ++标准库不提供正确的日期类型。C ++从C继承了日期和时间操作的结构体和函数。要访问与日期和时间相关的函数和结构，需要在C ++程序中包含

<ctime>

头文件。

有四个与时间相关的类型：

clock_t

，

time_t

，

size_t

，和

tm

。类型clock_t，size_t和time_t能够表示系统时间和日期作为某种整数。

结构类型

tm

以具有以下元素的C结构的形式保存日期和时间：

struct tm {
int tm_sec;   // seconds of minutes from 0 to 61
int tm_min;   // minutes of hour from 0 to 59
int tm_hour;  // hours of day from 0 to 24
int tm_mday;  // day of month from 1 to 31
int tm_mon;   // month of year from 0 to 11
int tm_year;  // year since 1900
int tm_wday;  // days since sunday
int tm_yday;  // days since January 1st
int tm_isdst; // hours of daylight savings time
}

使用

struct tm

来格式化时间，以下为演示Demo：

#include <iostream>
#include <ctime>

using namespace std;

int main( ) {
// current date/time based on current system
time_t now = time(0);

cout << "Number of sec since January 1,1970:" << now << endl;

tm *ltm = localtime(&now);

// print various components of tm structure.
cout << "Year: " << 1900 + ltm->tm_year<<endl;
cout << "Month: "<< 1 + ltm->tm_mon<< endl;
cout << "Day: "<<  ltm->tm_mday << endl;
cout << "Time: "<< 1 + ltm->tm_hour << ":";
cout << 1 + ltm->tm_min << ":";
cout << 1 + ltm->tm_sec << endl;
}

References

C++ Date and Time.